math
posted by Jon on .
Age 014 number of people= 206,423
Age 1534 number of people= 265,778
Age 3554 number of people= 308,946
Age 5574 number of people= 159,092
Age over 74 number of people= 69,264
1)Classify the data in the table.
A)positively skewed
B)negatively skewed
C)normally distributed
D)discrete distribution
My first choice was C but I went with A instead.
2)For 2000 patients, a bloodclotting time was normally distributed with a mean of 8 seconds. What percent had bloodclotting times between 5 and 11 seconds?
A)68%
B)34%
C)49/5%
D)47/5%
I chose A
3)During a sale, 1/6 of the CD prices are reduced. Find the probability that 2 of 4 randomlyselected CDs have reduced prices?
A)5/36
B)25/1296
C)25/216
D)5/216
I don't know
4)A music teacher wants to determine the music performances of students. A survey of which group would produce a random sample?
A)students in the school band
B)students attendeing the annual jazz concert
C)students in every oddnumbered homeroom
D)every other player on the baseball roster
I chose B
5)In an election poll, 56% of 400 voters chose a certain canidate. Find the margin of sampling error.
A)5%
B)2%
C)4%
D)7%
I chose A

1) sounds fine.
2) How can you determine the percentages without knowing the Standard Deviation? You need a measure of variability.
3) The probability of picking a reduced DC is 1/6, not reduced = 5/6. The probability of picking 2 of each is 1/6 * 1/6 * 5/6 * 5/6 (multiply).
4) A random sample means that every student has an equal probability of being in the sample. Reconsider your answer.
5) Right.
I hope this helps. Thanks for asking. 
I'm sorry #2 says For 2000 patients, a bloodclotting time was normally distributed with a mean of 8 seconds and a standard deviation of 3 seconds. What percent had bloodclotting times between 5 and 11 seconds?
Is #4 A?